Please be reminded that Upwork does not allow users to have multiple accounts. If you would like to be able to submit a proposal as a Freelancer, you will need to create a Freelancer account and get it approved.
You can be a Client and a Freelancer using the same account, or you can close your Client account once you open the Freelancer part of it. To create a Freelancer account on your existing account, please follow up instructions in this help article.
You will need to fill out your application and submit it for a review, please allow up to 24 hours for the review to be completed.